This invention relates to apparatus for separating photographic prints from negatives and, more particularly, it concerns apparatus for separating diffusion transfer prints from negative and carrier sheet assemblies after exposure and processing in photographic apparatus designed to handle such film components.
In the field of instant photography, the diffusion transfer method of obtaining a positive print or transparency from an exposed negative is well known and is adaptable to a variety of film constructions and/or assemblies of film components. In the early stages of diffusion transfer processing, initially separate positive and negative film components were supported on respective carrier sheets, the latter being connected at a leader so that after exposure of the negative in a camera, for example, the leader and carrier sheets enabled the positive and negative film components to come together in overlying coextensive relationship. Upon further removal of the film assembly from the camera, processing fluid was spread between the negative and positive sheets as the assembly exited from the camera. After an interval of time, referred to in the art as an inbibition period, the positive print was peeled from the negative and other components of the film assembly. The negative and other film components, including any residual processing fluid remaining on the negative or the carrier components, were discarded. Later in the evolution of diffusion transfer films, "integral" film units were developed in which the entire diffusion transfer chemistry was contained between two sheets permanently secured by an exterior frame component. Such integral film units represented an advance over the prior "peel-apart" units in the sense that the need for discarding part of the film unit as well as potential skin irritation and/or clothing damage by contact with the processing fluid were avoided.
At the present time, integral diffusion transfer film units are most commonly used in cameras designed primarily though not exclusively for the amateur photographer. On the other hand, many industrial or quasi-industrial applications of instant photography require the peel-apart film units quite similar to those developed during the early stages of diffusion transfer photography. In identification card cameras, for example, it is common practice to form two identification card formats on each standard-sized diffusion transfer print and later sever the two halves of the print for assembly in a laminated identification card. Quite obviously, the twin-sheet construction of integral film units does not lend itself to this use. The identification card industry is but an example of many other types of photographic industrial or laboratory type instant photography where the peel-apart film units are desirable.
While the disposal of the negative and other film components peeled from a positive print is not as great a problem to an industrial or laboratory environment as it might be to an amateur photographer, for example, the potential for skin irritation or clothing damage by the processing fluid remaining on the discarded components after separation from the positive print remains a problem, particularly in laboratories or installations where a single operator may be required to process or handle a large number of the peelapart units in a given work period. Also there is a need to await the length of time required for inbibition before the positive print is peeled from the disposed film components. These problems are adequate to justify an automated apparatus by which the positive print of a diffusion transfer film assemblage may be peeled from the other components and the other components discarded with a minimal amount of manual handling.